KR20000015988A - Swollen tobacco material manufacturing method - Google Patents

Abstract

PURPOSE: A swollen tobacco material manufacturing method can impregnate carbon dioxide with tobacco material. and provides the method cooling the tobacco material by the evaporation of liquid carbon dioxide. CONSTITUTION: The tobacco material is cooled the saturation temperature corresponding to impregnation pressure. The liquid carbon dioxide (21) is supplied from the upper side of the tobacco material TM via a sintered metal plate (13) with the impregnation pressure retained, the interior of the pressure vessel (11) is filled with carbon dioxide gas produced by the evaporation of liquid carbon dioxide, the tobacco material is impregnated with carbon dioxide by cooling the tobacco material with evaporation latentheat, The swollen tobacco material is attained by heat swell the carbon dioxide-impregnated tobacco material.

Description

Manufacturing method of expanded tobacco material

In order to reduce the amount of tobacco material used in tobacco products such as rolled cigarettes and to alleviate the taste of tobacco products and the like, swelling of the tobacco material is performed. This swelling is a technique for expanding and restoring dried and contracted tobacco tissue to a state close to the fresh leaves, and is an important technique in the manufacture of tobacco products.

Inflation of the tobacco material is basically performed by infiltrating the inflation aid into the tobacco tissue, followed by heating, thereby expanding the inflation aid by expanding the shrinkage of the inflated tissue.

As a method of expanding the tobacco material, a method of using carbon dioxide as the expanding aid is known.

For example, Japanese Unexamined Patent Application Publication No. 56-50830 discloses immersing tobacco material in liquid carbon dioxide under a pressure of about 24.6 to 31.6 kg / cm 2, impregnating the liquid carbon dioxide in the tobacco material, and converting the impregnated liquid carbon dioxide into solid carbon dioxide. And a method of expanding tobacco tissue by evaporating solid carbon dioxide at elevated temperature.

In this method, since the whole tobacco material is immersed in liquid carbon dioxide, the flavor component in tobacco material is extracted in liquid carbon dioxide, and the taste of an expanded tobacco material falls. In addition, the liquid carbon dioxide attached in large quantities to the tobacco material is converted into solid carbon dioxide, thereby fixing and freezing the resulting tobacco material. Adhering tobacco material needs to be unwound with a considerable amount of force before being provided to the heat expansion process, at which time yields fine powder, which is inappropriate for the production of cigar tobacco. So it is encouraged to immerse the tobacco material in the liquid carbon dioxide and then drain the liquid carbon dioxide from the tobacco material until the end of the continuous liquid flow of the liquid carbon dioxide, but not only adds time for draining. In addition, satisfactory results have not been obtained.

Japanese Unexamined Patent Application Publication No. 56-50952 discloses a method in which carbon dioxide is impregnated into a tobacco material in gaseous form and then expanded (expanded) by rapid heating thereof. This carbon dioxide gas expansion method can avoid the problem in the above method using liquid carbon dioxide, but since the amount of carbon dioxide retained in the tobacco material is small, it is easy to volatilize the carbon dioxide until the transition to the heating expansion process, Sufficient expansion of tobacco material is not achieved.

Japanese Unexamined Patent Publications No. 4-228055 and Japanese Patent Laid-Open No. 5-219928 disclose a method of expanding a cigarette that sufficiently cools the cigarette in advance in order to increase the amount of carbon dioxide impregnated by the condensation of carbon dioxide gas. More specifically, the method disclosed in Japanese Patent Laid-Open No. 4-228055 discloses cold gas carbon dioxide, carbon dioxide snow, and the like produced by introducing and expanding liquid carbon dioxide into the mixing tank while transferring the tobacco supplied in the horizontal mixing tank into the mixing tank. The tobacco is cooled by contacting and mixing with a mist-like cold mixture. The cooled tobacco is introduced into a vertical pressure tank connected with the mixing tank, and the cooled tobacco is brought into contact with gaseous carbon dioxide in this pressure tank to perform desired impregnation. In this method, not only a special device is required for preliminary cooling but also the heat exchange (heat transfer) state between the mist-like cold mixture (mainly snow) and the cigarette is likely to be localized, and the distribution (stain) is likely to occur at the cigarette temperature.

In addition, in the method disclosed in Japanese Patent Laid-Open No. 5-219928, preliminary cooling of the cigarette is performed by passing carbon dioxide gas through the cigarette. This preliminary cooling requires the circulation of carbon dioxide gas into the pressure vessel, which requires a separate circulation facility. Moreover, in this method, since the specific heat of the carbon dioxide gas used for cooling is small, it is necessary to make a cigarette contact with a large amount of carbon dioxide gas in order to cool a cigarette to the predetermined temperature low enough. In addition, since the cooling efficiency of the tobacco material is low in these conventional methods, not only a large amount of carbon dioxide is required for cooling but also precooling the cigarette, thereafter, carbon dioxide gas is introduced into the pressure vessel to a predetermined impregnation pressure for impregnation with carbon dioxide gas. When the pressure rises, the cigarette heats up due to the generated heat of compression. Therefore, excessive preliminary cooling to a lower temperature than necessary is not economical.

An object of the present invention is to swell the carbon dioxide material to be sufficiently impregnated in the tobacco material in a short time by using the required minimum amount of carbon dioxide, and the expanded swelling tobacco material having a high swelling rate of high quality can be produced using a device of a simple configuration. It is to provide a method for producing a tobacco material.

Disclosure of the Invention

The present invention provides a method of swelling tobacco material using carbon dioxide, mainly carbon dioxide gas, and provides a method of cooling tobacco material by latent heat of evaporation of liquid carbon dioxide for impregnation of tobacco material with carbon dioxide.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching the swelling method of the cigarette which mainly uses carbon dioxide gas in order to solve the said subject, in order to fully impregnate carbon dioxide with a tobacco material, the state of the carbon dioxide in a pressure container is a part which contacts the tobacco material. It is better to be in a thin liquid to mist-like saturated gas state, and to do so, it is effective to cool the tobacco material to a saturation temperature corresponding to the pressure (impregnation pressure) at the time of impregnation of carbon dioxide, and to cool the tobacco material. The use of latent heat of evaporation when carbon dioxide phase changes to carbon dioxide gas has been found to be very effective and has led to the completion of the present invention.

That is, the present invention utilizes the latent heat of evaporation of liquid carbon dioxide to cool the tobacco material contained in the pressure vessel so that the carbon dioxide is sufficiently impregnated with the tobacco material. The tobacco pressure vessel containing the tobacco material is pressurized with carbon dioxide gas to the desired impregnation pressure, and then liquid carbon dioxide is supplied to the tobacco material while maintaining this impregnation pressure. The supplied liquid carbon dioxide contacts the tobacco material and evaporates in the pressure vessel, saturating the pressure vessel with carbon dioxide gas. By the latent heat of evaporation of liquid carbon dioxide, the tobacco material is cooled to a temperature corresponding to the saturation temperature of the carbon dioxide corresponding to the impregnation pressure and sufficiently impregnated with carbon dioxide in the atmosphere in the pressure vessel. Puffed tobacco material is obtained by heat-swelling this carbon dioxide impregnated tobacco material.

In the present invention, when the entire tobacco material in the pressure vessel reaches the saturation temperature, the supply of liquid carbon dioxide may be stopped to immediately lower the pressure in the container (usually near atmospheric pressure) to remove the tobacco material, but the supply of liquid carbon dioxide may be stopped. After that, it is preferable to maintain a predetermined time until the pressure is released. In addition, the impregnation pressure is preferably at least the pressure (at about 4.3 kg / cm < 2 > in gauge pressure) at the starting point at which liquid carbon dioxide is converted into solid carbon dioxide, i. Further, the expansion of the tobacco material is preferably performed by bringing the tobacco material into contact with a hot air stream in an air flow dryer, and after the contact, the expanded tobacco material is separated from the hot gas stream.

That is, according to one aspect of the present invention,

(a) the tobacco material is placed in a pressure vessel;

(b) pressurizing the inside of the pressure vessel with a carbon dioxide gas to an impregnation pressure of at least about 4.3 kg / cm 2,

(c) while maintaining the impregnation pressure, supplying liquid carbon dioxide above the tobacco material to saturate the inside of the pressure vessel with carbon dioxide gas by evaporation of liquid carbon dioxide,

(d) after holding for a predetermined time, the pressure in the pressure vessel is reduced to almost atmospheric pressure,

(e) removing the tobacco material from the pressure vessel,

(f) supplying the removed tobacco material to the airflow dryer and contacting it with a high temperature airflow in the airflow dryer to swell the tobacco material;

(g) A method for producing a expanded tobacco material is provided, comprising each step of separating the expanded tobacco material in a high temperature air stream.

In addition, according to another aspect of the present invention,

(a) placing the tobacco material at the first temperature into a pressure vessel;

(b) pressurizing the inside of the pressure vessel with carbon dioxide gas to an impregnation pressure lower than the saturation pressure of the carbon dioxide gas at the first temperature,

(c) supplying the tobacco material from the tobacco material in the pressure vessel with a minimum amount of liquid carbon dioxide necessary for the tobacco material in the pressure vessel to reach a second temperature corresponding to the saturation temperature of the carbon dioxide gas at the impregnation pressure; Contacting the tobacco material and cooling the tobacco material to the second temperature by the latent heat of evaporation of liquid carbon dioxide, impregnating the carbon dioxide into the tobacco material,

(d) removing carbon dioxide-impregnated tobacco material from the pressure vessel;

(e) heating and expanding the carbon dioxide-impregnated tobacco material taken out;

Provided is a method for producing a expanded tobacco material.

The present invention relates to a method for producing a expanded tobacco material, and more particularly, to a method for producing a expanded tobacco material using carbon dioxide as an expansion aid.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows schematically an example of the impregnation apparatus used for impregnating tobacco material by carbon dioxide in the method of this invention.

Best Mode for Carrying Out the Invention

Hereinafter, the present invention will be described in more detail.

According to the present invention, the tobacco material is first put in a pressure vessel (impregnation vessel).

Tobacco materials are generally in the form of tobacco, but in the form of three pieces (small alumina), various kinds of tobacco varieties can be used.

The moisture content of the tobacco material is preferably 12% to 33% by dry weight, more preferably 12% to 25% by dry weight. In addition, the temperature (initial temperature) of the tobacco material at the time of introduction into the pressure vessel is generally set at 20 ° C to 30 ° C, which is equivalent to the room temperature in the factory by temperature control of the tobacco manufacturing plant. Housed in a container. Needless to say, tobacco material having a lower initial temperature or higher initial temperature may be used.

Then, the air in the pressure vessel containing the tobacco material is purged as usual. This purge can be performed by passing carbon dioxide gas through the pressure vessel or by depressurizing the inside of the pressure vessel using a vacuum pump.

After the purge is finished, the inside of the pressure vessel containing the tobacco material is pressurized with carbon dioxide gas to the desired impregnation pressure. This impregnation pressure is preferably at least the pressure at which the liquid carbon dioxide is converted into solid carbon dioxide, i.e., the pressure at the triple point of the carbon dioxide state diagram (about 4.3 kg / cm < 2 > in gauge pressure). By setting the impregnation pressure to a pressure higher than the pressure at the triple point of the carbon dioxide state diagram, there is no fear that the liquid carbon dioxide supplied later is converted into solid carbon dioxide and adhered to the pressure vessel wall, or the piping of the pressure vessel is prevented.

In the present invention, since the tobacco material is cooled by the latent heat of evaporation of liquid carbon dioxide, the impregnation pressure is more precisely that of the carbon dioxide gas at the initial temperature of the tobacco material contained in the pressure vessel (eg, 20 ° C to 30 ° C). It is defined as a pressure lower than the saturation pressure.

In the present invention, the impregnation pressure is 10 kg / cm 2 with the saturation temperature of carbon dioxide gas being about −37 ° C. in view of the softness of the tobacco material to low temperature (brittle) and the economics including the equipment for maintaining the impregnation system at low temperature. Gauge pressure) is more preferable.

The impregnation pressure is preferably as high as possible in order to achieve a higher expansion ratio of the tobacco material. However, carbon dioxide has a relatively low pressure and temperature threshold (74.2 kg / cm 2 (gauge pressure), 31.1 ° C.), and if the pressure and temperature are exceeded, the carbon dioxide cannot maintain the liquid phase, complicates the control system, and Since no improvement can be achieved, in practice, the impregnation pressure should not normally exceed about 74 kg / cm 2 (carbon dioxide gas saturation temperature of 31 ° C.) at the gauge pressure.

On the other hand, as the impregnation pressure is lower, the strength required for the pressure vessel may be lower, and the cost of the pressure vessel is reduced.

From the above, the actual impregnation pressure is set in consideration of the desired expansion ratio of the tobacco material, the amount of liquid carbon dioxide used (described below), the strength of the pressure vessel, workability, and the like. Usually, the impregnation pressure of 30-60 kg / cm <2> can be suitably used by gauge pressure because the product temperature of tobacco material is 20 degreeC-30 degreeC.

As described above, the carbon dioxide gas is introduced into the pressure vessel until the impregnation pressure, and the liquid carbon dioxide is supplied from the upper side of the tobacco material while maintaining the impregnation pressure.

The supply of liquid carbon dioxide is carried out through a sintered metal plate having a hole diameter of 2 to 200 μm, which is arranged to cross the opening of the pressure vessel at the bottom of the upper cover of the pressure vessel through one or more spray nozzles installed under the upper cover of the pressure vessel, or The spray nozzle may be provided on the outer circumferential wall near the open end of the pressure vessel, or by any other suitable means.

The amount of liquid carbon dioxide to be supplied can be defined as the minimum amount necessary for the tobacco material in the pressure vessel to reach a temperature corresponding to the temperature of saturated carbon dioxide gas at the impregnation pressure.

For example, as described above, the initial product temperature of the tobacco material is usually 20 ° C to 30 ° C, and the saturation pressure of carbon dioxide gas at this temperature is usually 57 to 72 kg / cm 2 as the gauge pressure. If the impregnation pressure is set to a pressure less than the saturation pressure of the carbon dioxide gas at the initial temperature of the tobacco material, the liquid carbon dioxide supplied in the pressure vessel containing the tobacco material will evaporate in contact with the tobacco material in the pressure vessel. The tobacco material is cooled by latent heat of evaporation. Therefore, when a controlled amount of liquid carbon dioxide is supplied into the pressure vessel, all of the liquid carbon dioxide vaporizes and becomes saturated in the pressure vessel, so that the product temperature of the tobacco material becomes the saturation temperature of the carbon dioxide gas at the impregnation pressure. The pressure in the pressure vessel is about to increase due to the evaporation of liquid carbon dioxide, but the pressure in the pressure vessel is appropriately discharged by using pressure holding means well known to those skilled in the art such as a pressure holding valve attached to the pressure vessel. It is easy to keep it at the impregnation pressure.

A method of obtaining the supply amount of liquid carbon dioxide is given by an example in which the impregnating pressure is 30 kg / cm2 at the gauge pressure using a tobacco material (cigarette) containing an initial product temperature of 25 ° C. and containing 25% moisture (dry weight basis). This will be described below.

(1) First, the amount of heat required to cool a tobacco cigarette in a temperature of 25 ° C. to a saturation temperature (−4.5 ° C.) of carbon dioxide gas at an impregnation pressure of 30 kg / cm 2 (gauge pressure) is obtained as follows.

(a) Specific heat of tobacco is slightly different depending on the type of raw material and also varies depending on the moisture content of tobacco. Can be considered. Thus, the specific heat of the tobacco moisture is 25% (0.25㎏H ₂ O / ㎏ dry tobacco) is about 0.6kcal / ㎏ ℃.

(b) Multiplying this value by the cooling temperature {25 ° C-(-4.5 ° C) = 29.5 ° C} yields about 18 kcal / kg of heat required for cooling per kg of dry tobacco (dry weight).

(2) The latent heat of evaporation of liquid carbon dioxide is described in the scientific literature, such as "International Units of Pure and Applied Chemistry" issued by Pagamon Press, and the Thermal Properties Collection by the Japan Society of Mechanical Engineers, and is 30 kg / ㎠ by gauge pressure. The latent heat of evaporation of liquid carbon dioxide at is about 60 kcal / kg.

(3) Therefore, the amount of liquid carbon dioxide required to cool the tobacco is equal to about 18 kcal / kg of the heat required to cool the tobacco, divided by about 60 kcal / kg of the latent heat of evaporation of the liquid carbon dioxide. That is, to cool 1 kg (dry weight) of tobacco, it is good to supply 0.29 kg of liquid carbon dioxide.

However, in reality, it is preferable to supply liquid carbon dioxide that is slightly excess than the calculated (theoretical) supply amount because there is an influence of the state of infiltration heat and pressure of the liquid carbon dioxide to be supplied and the temperature outside the pressure vessel. That is, the amount of liquid carbon dioxide to be supplied is preferably 1 to about 7 times, preferably 1.5 to 4 times the theoretical value.

Generally speaking, the ratio of the liquid carbon dioxide is preferably supplied at a ratio of 0.04 times to about 2.4 times the dry tobacco weight, preferably 0.06 times to about 1.4 times the weight of the tobacco material. This ratio is particularly suitable when the tobacco material contains 12% to 25% moisture on a dry weight basis, has an initial product temperature of 20 ° C to 30 ° C, and the impregnation pressure is 30 to 60 kg / cm2 at the gauge pressure. Do. The higher the impregnation pressure, the smaller the supply of carbon dioxide.

In this way, the tobacco material is cooled to the saturation temperature of the carbon dioxide gas at the impregnation pressure by the evaporative latent heat of the supplied liquid carbon dioxide, and is sufficiently impregnated with carbon dioxide.

When the supply amount of liquid carbon dioxide is small, all of the supplied liquid carbon dioxide is vaporized in a dry gas state, and thus the temperature of the tobacco material does not reach the saturation temperature, so that liquid carbon dioxide is added. This state can be detected by the temperature sensor provided in contact with the tobacco material. On the other hand, when the supply amount of liquid carbon dioxide is too large, the liquid carbon dioxide remains in some liquid state. This residual liquid carbon dioxide portion is collected at the bottom of the pressure vessel by gravity, and this may be recovered. This state can be monitored through an observation window provided at the bottom of the pressure vessel.

The fact that the pressure vessel reaches the saturation state of carbon dioxide can be confirmed by indicating the saturation temperature by the temperature sensor installed at the bottom of the tobacco material or at the bottom outlet (recovery pipe) of the pressure vessel. Alternatively, the point of time when the observation window confirms that even a small amount of liquid carbon dioxide is present at the bottom of the pressure vessel may be the point of time when the saturation state is reached.

After this, the supply of liquid carbon dioxide is stopped to release the pressure vessel to almost atmospheric pressure, and then the carbon dioxide-impregnated tobacco material is taken out of the pressure vessel and transferred to a heat expansion step to perform thermal expansion.

Tobacco material as it is taken out of the pressure vessel may have a shape in the container under the influence of the impregnation action, but even in this case, the tobacco material is not freeze or fixed, but is easily distorted when lightly gripped by a hand. In such a case, it is appropriate to release the tobacco material by passing the tobacco material between a pair of rollers each having a plurality of pins placed therein. By this release, the tobacco material is not crushed (that is, no debris, etc.). Therefore, the carbon dioxide impregnated tobacco material treated by the present invention can be transferred to a heat expansion step without being crushed.

In the heat expansion step, the carbon dioxide impregnated tobacco material is usually brought into contact with a high temperature air stream in an air flow dryer.

As air flow dryer is well known per se, hot air flows at high speed through an expansion tube made of stainless steel pipe. The hot air stream usually contains most of the water vapor.

In heat expansion, in general, the higher the heating temperature, the faster the expansion rate of carbon dioxide in the tobacco tissue, and a higher expansion ratio is obtained. However, in the present invention, since there is little or no solid carbon dioxide adhering to the tobacco material after impregnation, even if the expansion temperature is relatively low, the desired expansion ratio can be achieved. In any case, rapid heating is preferred for swelling the tobacco material, and it is preferable to dry it to moisture of 8% or less (based on dry weight), for example, to fix the expanded tobacco tissue once. As the rapid heating means, the air flow dryer is suitable. The heating temperature and time can be determined in consideration of the desired expansion ratio and flavor (for example, no burning odor). In the present invention, high swelling ratio can be achieved by contacting the hot air stream at about 260 ° C to 350 ° C for only 1 to 2 seconds.

Subsequent to expansion, the expanded tobacco material is separated from the hot gas. This separation can be performed by a tangential separator connected to an air flow dryer, as known in the art.

In addition, the pressure can be released after maintaining the state in order to ensure the impregnation of the carbon dioxide in the tobacco material without releasing the pressure immediately after the introduction of the liquid carbon dioxide and the pressure vessel reaches the saturation state. This holding time is preferably 10 seconds or more, and is sufficient to about 20 minutes. This holding time can be made shorter at lower impregnation pressures and shorter at higher impregnation pressures.

However, in the present invention, it was found that there is a correlation between the impregnation pressure and the initial moisture content in the tobacco material. As also shown in the examples shown below, it was found that the higher the impregnation pressure, the lower the initial moisture content (hereinafter, referred to as appropriate initial moisture amount) of the tobacco material which achieves the highest expansion ratio. For example, when the impregnation pressure is 30 kg / cm 2 as the gauge pressure, the initial moisture of the tobacco material is 20 to 25% (based on dry weight), and when the impregnation pressure is 40 kg / cm 2 as the gauge pressure, The initial moisture is 18 ~ 23% (dry weight basis). When the impregnation pressure is 50kg / ㎠ by gauge pressure, the initial moisture of tobacco material is 16 ~ 21% (dry weight basis), the highest at each impregnation pressure. The expansion ratio of the range is achieved.

The initial amount of titration may vary somewhat depending on the grade of tobacco material, the grade of the leaves, etc., but it is included in the above moisture range, especially when using blended tobacco in which various tobacco ingredients are mixed.

In addition, it has also been found that, when the tobacco material containing the appropriate initial moisture content is used, the higher the impregnation pressure, the higher the expansion ratio is achieved.

Another advantage of the high impregnation pressure is that the required minimum amount of liquid carbon dioxide to be used can be reduced, and the possibility of sticking of tobacco material after impregnation can be further eliminated. That is, for example, the saturation temperature of the carbon dioxide gas is about -4.5 deg. C at 30 kg / cm &lt; 2 &gt; as the gauge pressure, but is about +14.5 deg. C at 50 kg / cm &lt; 2 &gt; Therefore, the amount of heat (hence the amount of liquid carbon dioxide) required to cool the tobacco material at the initial product temperature of 20 to 30 ° C. to the saturation temperature is at least reduced as the impregnation pressure is higher. In addition, as described above, the appropriate initial moisture content of the tobacco material tends to be lower as the impregnation pressure is higher, so that the specific heat corresponding to the moisture content of the tobacco material is also reduced, so that the amount of heat required for cooling (and hence the amount of liquid carbon dioxide) is further reduced. In this way, the higher the impregnation pressure, the smaller the amount of liquid carbon dioxide used, the higher the temperature at which the tobacco material reaches during the impregnation (the slowing temperature of carbon dioxide gas), and the lower the appropriate moisture of the tobacco material. We can exclude more. In Tables 1 to 4, the impregnation pressure was 30 kg / cm 2 (saturation temperature -4.5 ° C., latent heat of evaporation of liquid carbon dioxide) and 40 kg / cm 2 (saturation temperature + 6.3 ° C., latent heat of liquid carbon dioxide). 50 kcal / kg), 50 kg / cm 2 (saturation temperature + 14.5 ° C., latent heat of vaporization of liquid carbon dioxide 43 kcal / kg) and 60 kg / cm 2 (saturation temperature + 22.0 ° C., latent heat of vaporization of liquid carbon dioxide 34 kcal / kg) The relationship between the initial moisture (based on dry weight) of tobacco material and the initial temperature of the tobacco material and the required minimum amount of liquid carbon dioxide (calculated value for 1 kg of tobacco material (based on dry weight)) in tobacco. Tables 1 to 4 show the initial moisture values of the tobacco material which achieves the highest expansion ratio at each impregnation pressure as optimum moisture.

Table 1: Required minimum amount of liquid carbon dioxide per kilogram of tobacco material at impregnation pressure 30 kg / cm 2 (gauge pressure) (kg)

Initial Moisture of Tobacco Materials Initial temperature of tobacco material 20 ℃ 25 ℃ 30 ℃ 12% 0.19 0.23 0.26 14% 0.20 0.24 0.28 16% 0.20 0.25 0.29 18% 0.21 0.26 0.30 20% 0.22 0.27 0.31 22% 0.23 0.28 0.32 24% (optimum) 0.24 0.29 0.33 25% 0.24 0.29 0.34

Table 2: Required minimum amount of liquid carbon dioxide per kilogram of tobacco material at impregnation pressure 40 kg / cm 2 (gauge pressure) (kg)

Initial Moisture of Tobacco Materials Initial temperature of tobacco material 20 ℃ 25 ℃ 30 ℃ 12% 0.13 0.17 0.22 14% 0.13 0.18 0.23 16% 0.14 0.19 0.24 18% 0.14 0.19 0.25 20% (optimum) 0.15 0.20 0.26 22% 0.15 0.21 0.27 24% 0.16 0.22 0.27 25% 0.16 0.22 0.28

Table 3: Required minimum amount of liquid carbon dioxide per kg of tobacco material at impregnation pressure 50 kg / cm 2 (gauge pressure) (kg)

Initial Moisture of Tobacco Materials Initial temperature of tobacco material 20 ℃ 25 ℃ 30 ℃ 12% 0.06 0.11 0.17 14% 0.06 0.12 0.17 16% 0.06 0.12 0.18 18% (optimum) 0.07 0.13 0.19 20% 0.07 0.13 0.19 22% 0.07 0.14 0.20 24% 0.07 0.14 0.21 25% 0.08 0.14 0.21

Table 4: Required minimum amount of liquid carbon dioxide per kilogram of tobacco material at impregnation pressure 60 kg / cm 2 (gauge pressure) (kg)

Initial Moisture of Tobacco Materials Initial temperature of tobacco material 25 ℃ 30 ℃ 12% 0.04 0.11 14% 0.04 0.11 16% (optimum) 0.04 0.12 18% 0.05 0.12 20% 0.05 0.13 22% 0.05 0.13 24% 0.05 0.14 25% 0.05 0.14

1 is a view schematically showing an example of an impregnation apparatus used to impregnate tobacco material by carbon dioxide in the method of the present invention. The impregnation apparatus 10 includes a pressure vessel (impregnation vessel) 11 for accommodating the tobacco raw material TM in the state accommodated in the metal mesh container MC. The pressure vessel 11 is made of, for example, stainless steel and has a cylindrical body. Opening and closing is freely attached to the upper opening end of the pressure vessel 11 so that the top cover 12 closes the pressure vessel 11 in an airtight manner.

At the bottom of the top cover 12, a liquid carbon dioxide spreading member 13 made of a porous sintered metal plate having a hole diameter of 2 to 200 mu m is provided at intervals from the bottom surface of the top cover 12. The dispersing member 13 has a planar shape that is the same as the inner cross-sectional plane shape of the pressure vessel 11, and the open end surface of the pressure vessel 11 when the pressure vessel 11 is hermetically closed by the top cover 12. It is arranged to cross.

The outer circumferential surface of the pressure vessel 11 prevents the intrusion of external heat into the pressure vessel, so that the impregnating pressure in the pressure vessel 11 is applied to the jacket 14 for maintaining the saturation temperature of the carbon dioxide gas in the pressure vessel 11. Covered. The jacket 14 can be circulated with a refrigerant or fruit necessary to maintain the saturation temperature.

The reservoir 20 for storing liquid carbon dioxide is disposed outside the pressure vessel 11. The upper part of the liquid carbon dioxide 21 in the reservoir 20 is filled with carbon dioxide gas 22.

The line L1 communicates with the upper portion of the reservoir 20 at the other end by communicating with the inside of the pressure vessel 11 through the top cover 12 at one end to supply the carbon dioxide gas 22 to the pressure vessel 11. Is installed. The line L1 is provided with an opening / closing valve V1 near the top of the pressure vessel 11. The supply and stop of supply of the carbon dioxide gas 22 into the pressure vessel 11 are controlled by opening and closing the valve V5.

A line L2 for supplying the liquid carbon dioxide 21 into the pressure vessel 11 is provided in communication with the bottom of the reservoir 20. In the liquid carbon dioxide supply line L2, an opening / closing valve V2, a liquid carbon dioxide supply pump P, a flow meter FM, and a pressure reducing valve V3 are sequentially provided on the reservoir 20 side. By opening the valve V2 and driving the supply pump P, the liquid carbon dioxide 21 in the reservoir 20 flows toward the pressure vessel 11. The flowmeter FM measures the flow rate of the liquid carbon dioxide and generates a signal for stopping the supply pump P when the set value of the calculated calculation is reached. In response to this signal, the supply pump P can be stopped. The pressure reducing valve V3 regulates the liquid carbon dioxide 21 supplied to the pressure vessel 11 through the line L2 to a predetermined pressure.

The line L2 branches into two lines L3 and L4 on the downstream side of the pressure reducing valve V3. Branch line L3 is joined to line L1 outside of pressure vessel 11. The other branch line L4 is connected to a spray nozzle (not shown) which is arranged toward the inside of the pressure vessel 11 around the upper portion of the pressure vessel 11.

The liquid carbon dioxide supplied through the line L3 is dispersed in the tobacco material TM through the holes of the sintered metal plate 13. In addition, the liquid carbon dioxide supplied through the line L4 is dispersed in the tobacco material TM in the spray nozzle. The supply of liquid carbon dioxide through the branch line L3 and the branch line L4 may be performed simultaneously or may be alternately performed appropriately. Therefore, the on-off valves V4 and V5 are provided in the line L3 and the line L4, respectively. In addition, since the supply of liquid carbon dioxide through the line L3 and the supply of liquid carbon dioxide through the line L4 may be performed only by one, either one of the lines L3 and L4 can be omitted. The valve V4 or V5 in the remaining lines L3 or L4 is also unnecessary. In addition, instead of the sintered metal plate 13, a disk provided with a plurality of spray nozzles may be provided so that the liquid carbon dioxide from the line L3 is scattered in the spray nozzles.

By the way, temperature measuring means, for example, thermocouples TC1, TC3, and TC2, are provided so as to be located at the upper, lower and middle portions of the tobacco material TM contained in the pressure vessel 11, respectively. The temperature is detected by the temperature detector TD outside the pressure vessel 11.

Further, a liquid carbon dioxide recovery tank 15 is disposed below the pressure vessel 11, and when the liquid carbon dioxide supplied to the pressure vessel 11 flows out slightly through the tobacco material TM, an on / off valve ( V6) receives this via line l5 equipped. The liquid carbon dioxide recovered by the recovery tank 15 is returned to the reservoir 20 through a recovery and purification process (not shown) through a line L6 provided with an on-off valve V7. In addition, a pressure release line L7 is connected to the line L5 upstream of the valve V6, and the pressure in the pressure vessel 11 can be released to almost atmospheric pressure by opening and closing the valve V8 provided therein. There is a number. Carbon dioxide gas discharged from the pressure release valve V8 through the line L7 is also sent to a recovery facility (not shown).

In addition, the upper portion of the pressure vessel 11 is provided with a line L8 in communication with the inside of the pressure vessel 11 and provided with a pressure regulating valve V9. The pressure holding valve V9 adjusts the pressure of the carbon dioxide gas in the pressure vessel 11 so as not to exceed the set impregnation pressure, and the impregnation pressure can be adjusted with good accuracy by cooperation with the pressure reducing valve V3. The carbon dioxide gas discharged from the pressure regulating valve V9 through the line L8 is also sent to a recovery facility (not shown).

In order to impregnate the tobacco material with carbon dioxide using the impregnation device 10, first, the tobacco material TM contained in the gold container vessel MC is put in the pressure vessel 11. After doing so, the top cover 12 is closed, the valve V1 is opened, and the valve V8 is opened, and carbon dioxide gas is passed through the pressure vessel 11 for a short time to purge the inside of the pressure vessel 11.

Then, the valve V8 is closed and the pressure vessel 11 is pressurized to the desired impregnation pressure by carbon dioxide gas. After completion of the pressurization, the valve V1 is closed, the valve V2 is opened, and the valve V4 and / or the valve V5 are opened to disperse liquid carbon dioxide above the tobacco material TM. When all of the thermocouples TC1 to TC3 exhibit the saturation temperature of the carbon dioxide gas at the impregnation pressure, the valve V2, further V4 and / or the valve V5 are closed to stop the supply of liquid carbon dioxide. Immediately thereafter or after a predetermined holding time has elapsed, the pressure release valve V8 is opened to release the pressure in the pressure vessel 11 to almost atmospheric pressure. After this, the top cover 12 is opened to take out the carbon dioxide-impregnated tobacco material and put it in an airflow dryer (not shown) for a predetermined heat expansion treatment.

As can be seen from the above description, the impregnation device 10 is a simple configuration in which a liquid carbon dioxide dispersing means is merely provided in a pressure vessel without requiring a separate device for precooling the tobacco material. According to the present invention, by incorporating carbon dioxide into tobacco material using such a simple configuration, an expanded cigarette having an excellent expansion ratio (expansion) is obtained after the expansion treatment.

Hereinafter, the Example of this invention is described with a comparative example. The apparatus used for impregnation of carbon dioxide in the following example has the same structure as the carbon dioxide impregnation apparatus shown in FIG. 1, and only the sintered metal plate 13 was used for the dispersion of the liquid carbon dioxide by this invention. The operation of the impregnation device was as described with reference to FIG. 1. In the examples below, the pressures are all gauge pressures.

In the following examples, each term is defined as follows.

Moisture: The weight decreased after one hour of the tobacco material sample is put into a natural convection oven at 100 ° C. It is expressed as the ratio of water to dry weight of tobacco material. In addition, this definition of moisture is applied throughout this specification.

Effervescence: A value indicating the filling capacity of tobacco material in the manufacture of tobacco cigarettes. The following densimeter was measured using a densimeter of type DD60A from Borgwaldt GmbH, Germany.

(1) A sample of tobacco material is filled into a cylindrical container (cylinder) having a diameter of 60 mm. As the sample, 15 g of the sample before the expansion treatment is used, and 10 g of the sample after the expansion treatment is used after rehumidification.

(2) Compress the filling tobacco material sample for 30 seconds with a piston of 56 mm in diameter with a load of 3 kg.

(3) The height of the layer of compressed tobacco material is indicated so that the apparent volume of tobacco material is obtained from the value. The value obtained by dividing this apparent volume by the weight of the tobacco sample is called volatility (in cc / g).

In addition, the higher the swelling value, the higher the filling capacity of the tobacco material, and the less the weight of the tobacco material filled per cigarette cigarette.

Expansion rate: The value obtained by dividing the swelling of the tobacco material after the swelling treatment by the swelling of the tobacco material before the swelling treatment. The larger this value, the better the charging capability.

CO ₂ retention: the increasing weight minutes to measure the weight of the sample to carbon dioxide (CO ₂₎ retention, and divided by the CO ₂ retention in sample weight (dry weight) of is settled values before and after the impregnation is referred to as CO ₂ retention .

Re-humidification: The swelling of tobacco material adjusted to the appropriate moisture for cigar tobacco. It is performed by standing for 1 week in a room at a temperature of 22 ° C. and a relative humidity of 60%.

Taste Quality: The result of sensory evaluation by ten panelists who have been trained professionally to judge the scent and taste of cigarettes. Each panel represents the taste quality in seven stages of -3, -2, -1, 0, +1, +2, and +3, and the average value is taken. The comparison object (reference) is 0, and the difference is shown as 1, the manufacturing method is different, and 2 is very different. The sign + indicates that the taste quality is good and the sign-indicates that the taste quality is bad. That is, -3 means that the taste quality is very bad, and +3 means that the taste quality is very good.

Example 1

Water was sprayed onto a representative tobacco blend piece (symbol: B-3) and humidified, and five types of samples having different initial moisture amounts as shown in Table 5 were prepared.

Each piece (about 100 g in dry weight) after 5 hours or more of humidification was put in a stainless steel mesh container and placed in a pressure vessel (1 liter of internal volume, 80 mm in diameter, and 200 mm in depth). The pressure vessel was then purged with carbon dioxide gas for 10 seconds.

Subsequently, carbon dioxide gas was introduced into the pressure vessel, and the pressure vessel was pressurized to an impregnation pressure of 30, 40, or 50 kg / cm 2.

After the supply of carbon dioxide gas was stopped, the supply of liquid carbon dioxide was started from above the pressure vessel. Liquid carbon dioxide was gradually dispersed until all of the thermocouples TC1 to TC3 located at the top, middle and bottom of the tobacco layer showed the saturation temperature of the carbon dioxide gas at the impregnation pressure.

Very little liquid carbon dioxide flowed out of the bottom of the pressure vessel at about the same time as the bottom thermocouple showed the saturation temperature.

One minute after stopping at this point, the pressure in the pressure vessel was released to atmospheric pressure for about 10 seconds to remove carbon dioxide-impregnated tobacco.

This tobacco was put into an airflow dryer, and heat expansion was performed.

The airflow dryer was made of a stainless steel pipe (expansion pipe) having an inner diameter of 84.9 mm and a length of 12 mm, and a high temperature air stream containing 86 volume% of water vapor flowed at a speed of 38 m / sec. The inlet temperature of the airflow dryer was controlled at 350 ° C. The passage time of the tobacco tube inflated was about 1 second. The expanded tobacco which passed through the expansion tube was taken out from the air stream in a tangential separator.

The moisture of the obtained expanded tobacco was 3 to 4%.

After re-humidification of each puffed tobacco, the swelling, swelling improvement and CO ₂ retention were measured. The results are shown in Table 5.

Table 5

Impregnation pressure Initial Moisture (%) Effervescent (cc / g) Expansion rate CO ₂ Retention Rate (%) 0 (no impregnation) 14.6 4.10 1.00 0 30 15.6 8.56 2.09 14.4 18.4 8.88 2.17 12.0 20.9 9.03 2.20 8.5 23.5 9.40 2.29 7.1 27.4 8.69 2.12 6.3 40 15.6 9.16 2.23 6.6 18.4 9.64 2.35 5.4 20.9 9.72 2.37 3.3 23.5 9.53 2.32 3.2 27.4 9.18 2.24 3.1 50 15.6 9.50 2.32 3.6 18.4 9.77 2.38 3.4 20.9 9.72 2.37 3.2 23.5 9.62 2.34 3.1 27.4 9.14 2.23 3.1

The results shown in Table 5 show that excellent swellability can be achieved by the method of the present invention. In addition, these results confirmed that the higher the impregnation pressure, the lower the initial moisture of the tobacco material, the improved the swelling.

In this embodiment, the same carbon dioxide impregnation treatment is performed under the conditions of obtaining the most expandable puffed tobacco (ie, impregnation pressure 50 kg / cm 2, initial moisture of 18.4% of tobacco), and then the carbon dioxide impregnated tobacco is placed in a vacuum insulated container of stainless steel. It was preserved and left. After leaving for 30 minutes, heat expansion was performed in an airflow dryer in the same manner. The temperature of the tobacco in the insulated container was maintained at -40 ° C. even after it was left to stand.

In general, in order to minimize the amount of carbon dioxide volatilized in the tobacco tissue, carbon dioxide-impregnated tobacco material is preferably heat-expanded immediately after impregnation. However, according to the present invention from the above results, it was found that when the appropriate cooling means was impregnated with about 3% (dry weight basis) of carbon dioxide in the tobacco tissue, a sufficient expansion effect was obtained.

Example 2

Humidification was sprayed with water so that the moisture of domestic yellow species tobacco (symbol: ESE) was 25%. About 100 g of humidified tobacco tobacco (dry weight basis) of 5 hours or more was put in a stainless steel gold container and placed in the same impregnation apparatus as in Example 1, and then purged with carbon dioxide gas for 10 seconds.

Subsequently, after pressurizing to 30 kg / cm <2> with carbon dioxide gas, liquid carbon dioxide was disperse | distributed. After 12 seconds, all three thermocouples TC1 to TC3 positioned in the tobacco showed a saturation temperature corresponding to 30 kg / cm 2 of carbon dioxide, that is, -4.5 ° C. At this point, the supply of liquid carbon dioxide was stopped. The amount of liquid carbon dioxide supplied was 68 g.

Eight seconds after stopping the supply of liquid carbon dioxide, the pressure in the pressure vessel was released to atmospheric pressure for about 10 seconds.

The time required for the impregnation treatment (after pressurization with carbon dioxide gas to end of release to atmospheric pressure), that is, the impregnation time was about 30 seconds.

Immediately after releasing the pressure, the tobacco was taken out and weighed. It was 143.8 g. Since the weight of the tobacco tobacco before impregnation treatment with carbon dioxide was 122.1 g, the tobacco tobacco after impregnation had 21.7 g of carbon dioxide. This corresponds to 22.1% by weight of dry tobacco.

The carbon dioxide-impregnated tobacco was kept in a cylindrical shape corresponding to the inside of the pressure vessel, but when it was lightly gripped by hand, it was easily broken and there was no fixation.

This carbon dioxide-impregnated tobacco was heat-expanded in the same airflow dryer as in Example 1. The moisture of the obtained expanded tobacco was 3.4%. After re-humidity, the swelling was measured and found to be 9.42 cc / g. In addition, the bloat of untreated tobacco was 4.09 cc / g.

Next, the retention time was changed, and the same impregnation and inflation treatment were carried out using the same lot of humidified tobacco.

All the above results are shown in Table 6 below. Table 6 also describes the impregnation time.

Table 6

Holding time (impregnation time) CO ₂ retention rate Bloat 8 seconds (30 seconds) 22.1 9.42 38 seconds (1 minute) 20.7 9.34 4 minute, 38 seconds (5 minutes) 17.2 9.38 7 minute, 38 seconds (8 minutes) 15.5 9.40 9 minute, 38 seconds (10 minutes) 14.2 9.37

As can be seen from the results shown in Table 6, as the holding time increases, a small amount of excess liquid carbon dioxide gathers at the bottom of the pressure vessel by weight, but the CO ₂ retention rate tends to decrease. Regardless, it was excellent. Therefore, it became clear that good swellability can be achieved even with a short impregnation time of 30 seconds by dispersing the required minimum amount of liquid carbon dioxide and cooling the tobacco raw material reliably.

Comparative Example 1

The humidification tobacco used in Example 2 was used to impregnate carbon dioxide according to the method of Example described in Japanese Unexamined Patent Application Publication No. 56-50830. That is, in the pressure vessel used in Example 2, the same humidified tobacco was purged with carbon dioxide gas, and the liquid carbon dioxide was supplied into the pressure vessel until the liquid carbon dioxide was ejected from the pressure holding valve V9 at the upper portion of the pressure vessel. The time until the liquid carbon dioxide was filled in the pressure vessel depends on the volume of the pressure vessel, the pump capacity, the size of the pipe and the supply valve, but in this comparative example, a time of 1 minute and 30 seconds was required.

The liquid carbon dioxide was then removed from the pressure vessel into the recovery tank. It took a minute to pull it out.

After the continuous discharge of liquid carbon dioxide was completed, the valve V6 was closed and the pressure was released to atmospheric pressure after the draining time shown in Table 7 was passed to drain the water. The time required for pressure releasing was about 10 seconds as in Example 1.

Therefore, the time required for the impregnation treatment other than the purge time was required for 2 minutes and 40 seconds in addition to the draining time after the draining.

The impregnated tobacco which had been taken out was solid and was hardly disperse | distributed by hand, and heat-expanded by the airflow dryer on the conditions similar to Example 1. The results are shown in Table 7.

TABLE 7

Drain time after draining CO ₂ retention rate Effervescent (cc / g) none 26.2 9.36 3 minutes 24.4 9.12 5 minutes 22.9 9.21

In impregnation by immersion of liquid carbon dioxide, it is effective to reduce the carbon dioxide retention rate and reduce the solidification of the impregnated tobacco by providing a predetermined draining time for draining after draining. However, even after taking 5 minutes of draining time after removal of water, it was only about the same as the retention rate in the case of the impregnation time of 30 second in Example 2, and swelling was also slightly inferior. This is considered to be because when the entire tobacco material is immersed in liquid carbon dioxide, excess liquid carbon dioxide is present in the tobacco material, and liquid carbon dioxide remains in the gap between the tobacco materials even if the continuous flow of liquid carbon dioxide stops.

Example 3

Carbon dioxide was impregnated in the same manner as in Example 1 to the tobacco material (cigarette) each containing the initial moisture showing the highest swellability under three levels of impregnation pressure in Example 1. The tobacco material taken out was heat-expanded using the airflow dryer different from the airflow dryer used in Example 1. The airflow dryer used in this example was 20m in length of the expansion tube, and the inlet temperature was controlled at 180 ° C or 260 ° C. The velocity of the air flow was the same as in Example 1. The results obtained are shown in Table 8 below. In Table 8, the result under the heat expansion conditions of Example 1 was also written together.

Table 8

Impregnation pressure (㎏ / ㎠) (initial moisture) Air flow condition 200 ℃ 2 seconds 260 ° C 2 seconds 350 ℃ 1 second 30 (23.5%) 8.76 9.38 9.40 40 (20.9%) 8.95 9.69 9.72 50 (18.4%) 9.11 9.79 9.77

As is clear from the results in Table 8, by the heat expansion treatment at 260 ° C. for 2 seconds, the same swellability as in the case of the heat expansion treatment at 350 ° C. for 1 second was obtained. The swelling by heat expansion treatment at 200 ° C. for 2 seconds was slightly lower than this, but high.

Example 4

In this example, the blended tobacco (B-3; 25% initial moisture) was swelled in the same manner as in Example 2 using a pressure vessel having a capacity of 10 liters (diameter 200 mm, depth 320 mm).

That is, about 1250 g (1000 g in dry weight) of blended tobacco was charged into a pressure vessel, and then pressurized to 30 kg / cm 2 by carbon dioxide gas to 790 g of liquid carbon dioxide. The supply of this liquid carbon dioxide corresponds to 79% of the blended tobacco on a dry weight basis.

Pressurization to the impregnation pressure by carbon dioxide gas and dispersion of liquid carbon dioxide were performed for 1 minute. One minute after the completion of the supply of liquid carbon dioxide, all three thermocouples TC1 to TC3 in the blended tobacco layer showed a saturation temperature (-4.5 ° C).

Holding time was taken 0 minutes (none), 3 minutes, or 8 minutes, and the pressure in a pressure vessel was released to atmospheric pressure for about 30 second after that.

The blended tobacco smoked out was passed through a tobacco smoke release device consisting of a pair of rollers each having a plurality of pins 30 mm in length, and then heat-expanded in an airflow dryer under the same conditions as in Example 1. The results are shown in Table 9 below.

Comparative Example 2

The same blended tobacco was immersed in liquid carbon dioxide by the method of Comparative Example 1 using the pressure vessel used in Example 4, and then treated.

In this Comparative Example 2, a time of 8 minutes was required to immerse the blended tobacco in liquid carbon dioxide and 2 minutes was required to drain the liquid carbon dioxide.

After the draining time of 0 minutes (none), 3 minutes or 8 minutes, the pressure in the pressure vessel was released to atmospheric pressure for about 30 seconds.

The blended tobacco tobacco taken out was passed through the tobacco tobacco deactivator used in Example 4 and heat-swelled under the same conditions in the same airflow dryer.

The results are written together in Table 9 below. In Table 9, "elapsed time" means the retention time in Example 4, and in Comparative Example 2 means the draining time.

Table 9

Elapsed time (minutes) CO ₂ Retention Rate (%) Effervescent (cc / g) Example 4 Comparative Example 2 Example 4 Comparative Example 2 none 14.2 43.8 8.96 8.89 3 minutes 10.4 32.1 8.85 8.78 8 minutes 8.0 27.7 8.99 8.81

As is clear from Table 9, according to the method of the present invention for dispersing liquid carbon dioxide, since almost no extra carbon dioxide is used, the impregnation time can be shorter than the method of dipping liquid carbon dioxide in any device scale. If the impregnation time is shortened, the throughput per unit time can be increased or the apparatus can be miniaturized.

In addition, the use of a pressure vessel with a large volume greatly varies the carbon dioxide retention rate by the liquid carbon dioxide dispersion method of the present invention and the conventional liquid carbon dioxide immersion method (see Table 9). In the conventional immersion method, extra carbon dioxide remains quite, and the carbon dioxide retention rate is about 28% even after 8 minutes of drainage. The lower half of the pulled-out tobacco was markedly fixed and did not crumble even when held by hand, so it was necessary to dissolve the mass using a tobacco-releaser. Extra carbon dioxide, such as sticking to tobacco, is difficult to recover and is undesirable because of the potential for adverse effects on the environment and manufacturing cost.

In addition, since the method of the present invention by the dispersion of liquid carbon dioxide effectively uses a predetermined minimum required amount of carbon dioxide, there is almost no extra carbon dioxide. Thus, the removed tobacco was not stuck and was scattered from the beginning and almost passed through the rollers of the tobacco releaser.

Next, in Example 4 and Comparative Example 2, the holding time was 8 minutes, and the tobacco smoke after puffing was divided into sieves by both methods. As a sieve machine, the sieve was established by the International Standardization Organization (ISO) and the Japanese Industrial Standards (JIS) as a sieve using the PRUEFSIB JEL200 type from J. Engelsmann AG of Germany. 4.00, 3.15, 2.00, The sieves of 1.00 and 0.50 mm were overlapped and installed in the sieve machine.

First, bulging tobacco was sufficiently mixed, compressed and divided to weigh 25g. This tobacco was placed in a sieve for 2 minutes, and the weight of the tobacco smoke remaining on each body and the tobacco passed through a 0.50 mm sieve was accurately weighed to determine the respective ratios to the weight of the first tobacco (25 g). This measurement operation was repeated 8 times with respect to a sample and the average value was calculated | required. The results are shown in Table 10.

Table 10

4 mm or more Less than 4 mm to 3.15 mm 3.15 mm or less Less than 2mm ~ 1mm Less than 1 mm to 0.5 mm Less than 0.50mm Example 4 10.2 9.4 29.4 40.0 7.6 3.4 Comparative Example 2 3.1 4.0 19.2 53.0 15.6 5.1

If the tobacco sticks, it will break when you release it. Fine tobacco cigarettes (subdivisions) such as passing through a sieve of 1 mm are unsuitable for the production of rolled tobacco, and the yield decreases.

As can be seen from Table 10, in the conventional carbon dioxide immersion method, the fixation of the impregnated tobacco is remarkable, so that there is a lot of crumbs due to the release of the tobacco, and the overall length of the tobacco is shorter as compared with the liquid carbon dioxide scattering method of the present invention. In particular, the proportion of subdivisions that passed through a 1 mm sieve exceeded 20%.

On the other hand, the liquid carbon dioxide spreading method of the present invention passes through the tobacco release device almost as it is, so that the impregnation of tobacco smoke is small and the fraction is 11%, which is half of that by the conventional dipping method.

Next, the remaining puffed tobacco used for sieving was rolled up with rolled tobacco, and taste comparisons were made without revealing the treatment method. When the determination result was 0 by the conventional immersion method, it was +2 by the dispersion method of this invention, and it was clearly excellent in taste quality. It is considered that this is due to the conventional immersion method, in particular, because the liquid carbon dioxide dissolves the volatile components and thus the smell of tobacco is lost.

As described above, according to the present invention, carbon dioxide can be impregnated into tobacco material in a short time by using the minimum amount of carbon dioxide required, and an expanded swelling tobacco material having excellent quality can be manufactured by using a device having a simple configuration.

Claims (27)

(a) the tobacco material is placed in a pressure vessel; (b) pressurizing the inside of the pressure vessel with a carbon dioxide gas to an impregnation pressure of at least about 4.3 kg / cm 2, (c) supplying liquid carbon dioxide from the top of the tobacco material while maintaining its impregnation pressure, and saturating the inside of the pressure vessel with carbon dioxide gas by evaporation of liquid carbon dioxide; (d) After holding for a predetermined time, the pressure in the pressure vessel is reduced to almost atmospheric pressure, (e) removing tobacco material from the pressure vessel; (f) supplying the removed tobacco material to the airflow dryer and contacting the airflow at high temperature in the airflow dryer to swell the tobacco material; (g) A method for producing a expanded tobacco material, comprising the steps of separating the expanded tobacco material from a high temperature air stream. The method according to claim 1, wherein the tobacco material in step (a) has a moisture content of 12% to 33% on a dry weight basis. The production method according to claim 1, wherein the tobacco material in step (a) is at a temperature of 20 ° C to 30 ° C. The method according to claim 1, wherein the impregnation pressure in the step (b) is 10 to 74 kg / cm 2 by gauge pressure. The production method according to claim 4, wherein the impregnation pressure in the step (b) is 30 to 60 kg / cm 2 by gauge pressure. The process according to claim 1, wherein the higher the impregnation pressure in the step (b), the less moisture is used in the step (a). The process according to claim 1, wherein the supply amount of liquid carbon dioxide in step (c) is 0.04 times to about 2.4 times the weight of the tobacco material on a dry weight basis. 8. A process according to claim 7, wherein the supply amount of liquid carbon dioxide in step (c) is from 0.06 times to about 1.4 times the weight of the tobacco material on a dry weight basis. The production method according to claim 1, wherein in step (c), the supply of liquid carbon dioxide is stopped immediately after the temperature of the tobacco material reaches the saturation temperature of the carbon dioxide gas at the impregnation pressure. The method according to claim 1, wherein in step (c), the supply of liquid carbon dioxide is stopped when the liquid carbon dioxide slightly flows out from the bottom of the pressure vessel. The production method according to claim 1, wherein the holding time in step (d) is 10 seconds or more. The method according to claim 1, wherein the hot air stream in the step (f) contains water vapor and has a temperature of 260 ° C to 350 ° C. 13. A process according to claim 12, wherein in step (f) the tobacco material is brought into contact with the hot air stream for 1 to 2 seconds. The method according to claim 1, wherein in the step (f), the tobacco material is swelled until the moisture content is 8% or less on a dry weight basis. (a) placing the tobacco material at the first temperature into a pressure vessel; (b) pressurizing the inside of the pressure vessel with carbon dioxide gas to an impregnation pressure lower than the saturation pressure of the carbon dioxide gas at the first temperature, (c) supplying to the tobacco material at least the amount of liquid carbon dioxide necessary for the tobacco material in the pressure vessel to reach a second temperature corresponding to the saturation temperature of the carbon dioxide gas at the impregnation pressure; Contacting the tobacco material and cooling the tobacco material to the second temperature by latent heat of evaporation of liquid carbon dioxide, impregnating the carbon dioxide into the tobacco material, (d) removing carbon dioxide-impregnated tobacco material from the pressure vessel; (e) A method for producing a expanded tobacco material comprising a step of thermally expanding a carbon dioxide-impregnated tobacco material taken out. The production process according to claim 15, wherein the first temperature in the step (a) is a temperature of 20 ° C to 30 ° C. 16. The process according to claim 15, wherein the tobacco material in step (a) has a moisture content of 12% to 25% on a dry weight basis. The production method according to claim 15, wherein the impregnation pressure in the step (b) is equal to or greater than the pressure at the triple point of carbon dioxide and less than the pressure at the critical point. The production method according to claim 18, wherein the impregnation pressure in the step (b) is 10 to 74 kg / cm 2 as gauge pressure. 16. The process according to claim 15, wherein the higher the impregnation pressure in step (b), the less moisture is used in step (a). The production method according to claim 15, wherein the supply amount of liquid carbon dioxide in step (c) is 1 to 7 times the theoretical amount. 22. A process according to claim 21, wherein the supply amount of liquid carbon dioxide in step (c) is from 1.5 times to about 4 times the theoretical amount. The production method according to claim 15, wherein in step (c), the supply of liquid carbon dioxide is stopped immediately after the temperature of the tobacco material reaches a second temperature. The production method according to claim 15, wherein the supply of liquid carbon dioxide is stopped at a time point when the liquid carbon dioxide slightly flows out from the bottom of the pressure vessel in the step (c). 16. The process according to claim 15, wherein in step (e) the carbon dioxide impregnated tobacco material is brought into contact with an air stream comprising water vapor at a temperature of 260 ° C to 350 ° C. A process according to claim 25, wherein in step (e) the carbon dioxide impregnated tobacco material is brought into contact with the air stream for 1 second to 2 seconds. The production method according to claim 15, wherein in the step (e), the tobacco material is expanded until the moisture content is 8% or less on a dry weight basis.